The mRNA expression of insulin-like growth factor-1 (Igf1) is decreased in the rat frontal cortex following gamma-hydroxybutyrate (GHB) administration. (12th April 2017)

• Record Type: Journal Article
• Authors: Brolin, Erika; Johansson, Jenny; Zelleroth, Sofia; Diwakarla, Shanti; Nyberg, Fred; Grönbladh, Alfhild; Hallberg, Mathias
• Is Part Of: Neuroscience letters. Volume 646(2017)
• Page Start: 15
• Page End: 20
• Publication Date: 2017-04-12
• Subjects: Growth hormone (GH) -- Gamma-hydroxybutyrate (GHB) -- Insulin-like growth factor-1 (IGF-1) -- Central nervous system (CNS) -- Frontal cortex (FC) -- Cognition; Neurology -- Periodicals; Neurology -- Periodicals; Research -- Periodicals; Neurologie -- Périodiques; Neuroanatomie -- Périodiques; Neuropharmacologie -- Périodiques; Neurophysiologie -- Périodiques; Neurology; Periodicals; Electronic journals; 617.48
• DOI: 10.1016/j.neulet.2017.02.053
• Languages: English
• ISSNs: 0304-3940

Abstract

Highlights: GHB affects gene expression related to the somatotrophic axis in the rat brain. GHB exposure down-regulates Igf1 mRNA expression in the rat frontal cortex. A correlation between Igf1 and Ghr mRNA expression is observed in several brain areas. Abstract: In recent years, growth hormone (GH), together with its secondary mediators insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-2 (IGF-2), have been highlighted for their beneficial effects in the central nervous system (CNS), in particular as cognitive enhancers. Cognitive processes, such as learning and memory, are known to be impaired in individuals suffering from substance abuse. In the present study, we investigated the effect of gamma-hydroxybuturate (GHB), an illicit drug used for its sedating and euphoric properties, on genes associated with the somatotrophic axis in regions of the brain important for cognitive function. Sprague Dawley rats ( n = 36) were divided into three groups and administered either saline, GHB 50 mg/kg or GHB 300 mg/kg orally for seven days. The levels of Ghr, Igf1 and Igf2 gene transcripts were analyzed using qPCR in brain regions involved in cognition and dependence. The levels of IGF-1 in blood plasma were also determined using ELISA. The results demonstrated a significant down-regulation of Igf1 mRNA expression in the frontal cortex in high-dose treated rats. Moreover, a significant correlation between Igf1 and Ghr mRNA expression was found in the hippocampus, the frontal cortex, and the caudate putamen, indicating local regulation of the GH/IGF-1 axis. To summarize, the current study concludes that chronic GHB treatment influences gene expression of Ghr and Igf1 in brain regions involved in cognitive function.